1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_BASE64_H
58 #define OPENSSL_HEADER_BASE64_H
59 
60 #include <openssl/base.h>
61 
62 #if defined(__cplusplus)
63 extern "C" {
64 #endif
65 
66 
67 /* base64 functions.
68  *
69  * For historical reasons, these functions have the EVP_ prefix but just do
70  * base64 encoding and decoding. */
71 
72 
73 /* Encoding */
74 
75 /* EVP_EncodeBlock encodes |src_len| bytes from |src| and writes the
76  * result to |dst| with a trailing NUL. It returns the number of bytes
77  * written, not including this trailing NUL. */
78 OPENSSL_EXPORT size_t EVP_EncodeBlock(uint8_t *dst, const uint8_t *src,
79                                       size_t src_len);
80 
81 /* EVP_EncodedLength sets |*out_len| to the number of bytes that will be needed
82  * to call |EVP_EncodeBlock| on an input of length |len|. This includes the
83  * final NUL that |EVP_EncodeBlock| writes. It returns one on success or zero
84  * on error. */
85 OPENSSL_EXPORT int EVP_EncodedLength(size_t *out_len, size_t len);
86 
87 
88 /* Decoding */
89 
90 /* EVP_DecodedLength sets |*out_len| to the maximum number of bytes that will
91  * be needed to call |EVP_DecodeBase64| on an input of length |len|. It returns
92  * one on success or zero if |len| is not a valid length for a base64-encoded
93  * string. */
94 OPENSSL_EXPORT int EVP_DecodedLength(size_t *out_len, size_t len);
95 
96 /* EVP_DecodeBase64 decodes |in_len| bytes from base64 and writes
97  * |*out_len| bytes to |out|. |max_out| is the size of the output
98  * buffer. If it is not enough for the maximum output size, the
99  * operation fails. It returns one on success or zero on error. */
100 OPENSSL_EXPORT int EVP_DecodeBase64(uint8_t *out, size_t *out_len,
101                                     size_t max_out, const uint8_t *in,
102                                     size_t in_len);
103 
104 
105 /* Deprecated functions.
106  *
107  * OpenSSL provides a streaming base64 implementation, however its behavior is
108  * very specific to PEM. It is also very lenient of invalid input. Use of any of
109  * these functions is thus deprecated. */
110 
111 /* EVP_EncodeInit initialises |*ctx|, which is typically stack
112  * allocated, for an encoding operation.
113  *
114  * NOTE: The encoding operation breaks its output with newlines every
115  * 64 characters of output (48 characters of input). Use
116  * EVP_EncodeBlock to encode raw base64. */
117 OPENSSL_EXPORT void EVP_EncodeInit(EVP_ENCODE_CTX *ctx);
118 
119 /* EVP_EncodeUpdate encodes |in_len| bytes from |in| and writes an encoded
120  * version of them to |out| and sets |*out_len| to the number of bytes written.
121  * Some state may be contained in |ctx| so |EVP_EncodeFinal| must be used to
122  * flush it before using the encoded data. */
123 OPENSSL_EXPORT void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, uint8_t *out,
124                                      int *out_len, const uint8_t *in,
125                                      size_t in_len);
126 
127 /* EVP_EncodeFinal flushes any remaining output bytes from |ctx| to |out| and
128  * sets |*out_len| to the number of bytes written. */
129 OPENSSL_EXPORT void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, uint8_t *out,
130                                     int *out_len);
131 
132 /* EVP_DecodeInit initialises |*ctx|, which is typically stack allocated, for
133  * a decoding operation.
134  *
135  * TODO(davidben): This isn't a straight-up base64 decode either. Document
136  * and/or fix exactly what's going on here; maximum line length and such. */
137 OPENSSL_EXPORT void EVP_DecodeInit(EVP_ENCODE_CTX *ctx);
138 
139 /* EVP_DecodeUpdate decodes |in_len| bytes from |in| and writes the decoded
140  * data to |out| and sets |*out_len| to the number of bytes written. Some state
141  * may be contained in |ctx| so |EVP_DecodeFinal| must be used to flush it
142  * before using the encoded data.
143  *
144  * It returns -1 on error, one if a full line of input was processed and zero
145  * if the line was short (i.e. it was the last line). */
146 OPENSSL_EXPORT int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, uint8_t *out,
147                                     int *out_len, const uint8_t *in,
148                                     size_t in_len);
149 
150 /* EVP_DecodeFinal flushes any remaining output bytes from |ctx| to |out| and
151  * sets |*out_len| to the number of bytes written. It returns one on success
152  * and minus one on error. */
153 OPENSSL_EXPORT int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, uint8_t *out,
154                                    int *out_len);
155 
156 /* EVP_DecodeBlock encodes |src_len| bytes from |src| and writes the result to
157  * |dst|. It returns the number of bytes written or -1 on error.
158  *
159  * WARNING: EVP_DecodeBlock's return value does not take padding into
160  * account. It also strips leading whitespace and trailing
161  * whitespace and minuses. */
162 OPENSSL_EXPORT int EVP_DecodeBlock(uint8_t *dst, const uint8_t *src,
163                                    size_t src_len);
164 
165 
166 struct evp_encode_ctx_st {
167   /* data_used indicates the number of bytes of |data| that are valid. When
168    * encoding, |data| will be filled and encoded as a lump. When decoding, only
169    * the first four bytes of |data| will be used. */
170   unsigned data_used;
171   uint8_t data[48];
172 
173   /* eof_seen indicates that the end of the base64 data has been seen when
174    * decoding. Only whitespace can follow. */
175   char eof_seen;
176 
177   /* error_encountered indicates that invalid base64 data was found. This will
178    * cause all future calls to fail. */
179   char error_encountered;
180 };
181 
182 
183 #if defined(__cplusplus)
184 }  /* extern C */
185 #endif
186 
187 #endif  /* OPENSSL_HEADER_BASE64_H */
188